Information
Level 2 Detail of experimental conditions (what might be found in a journal paper or project brief in Hydstra)
Description of study
What?
Four studies examined the effect of raised beds on a range of variables on cropping land in Victoria.
When and Where?
The experimental site was near Mt Pollock, 30 km west of Geelong in south-western Victoria. The soil and landscape at this site were typical of much of the country used locally for crop and pasture production. The soil had a sandy clay loam (0–0.15 m) in the A horizon and a gravely clay in the B horizon. It was classified as a vertic, subnatric, grey Sodosol.
How?
Holland et al (2007)
This study focused on 2 tillage treatments: raised beds and conventional cultivation. Initially, the raised bed plots were deep cultivated (to 0.25m depth). The soil was then formed into beds 2m wide and approximately 0.30m high with furrows (0.40m wide) separating the beds. The conventional cultivation was tilled to a shallow depth (<50 mm) and had no furrows. Subsequently, a minimum tillage policy was adopted and the only cultivation the raised beds received was occasionally (every 3 years or so) to ‘clear out’ the furrows.
The plots for each treatment were established in 1999 before which the site was permanent pasture. The experimental design was a randomised block containing 0.2 ha plots (20m width, 100m length). Each treatment was replicated 3 times across the field in an east–west direction.
Aluminium cylinders (100mm diameter, 75mm height) were used to take undisturbed soil cores at 2 times: the beginning of the growing season in June 2003 and post-harvest in February 2004. In the laboratory, cores were put into an oven at 40oC for at least 24 h before they were resin-impregnated. The sections were photographed under UV light using a digital camera and the images were processed to segment the solid and pore components using a procedure based on the watershed extraction method.
Holland et al (2008)
The volumetric water content (Ɵv) at the soil surface was measured with ThetaProbes®. A hand-held ThetaProbe was used to take spot readings throughout the growing season. They were taken 8 times in each plot and replicated 3 times for each treatment. Plant growth and grain yield measurements were taken on wheat in 2003 and barley in 2004. Dry matter samples (5 quadrants 0.5 by 1m per plot) were collected twice during the growing season. The first dry matter sample was taken at the late tillering stage, the second at anthesis, and at harvest the total plant dry matter was measured.
An automatic weather station (Handar with Vaisala sensors) was installed at Mt Pollock to record air temperature, wind speed, solar radiation, and rainfall. A comparison of the means of the surface Ɵv, plant growth and grain yield data was made using an analysis of variance (ANOVA)
Holland et al (2012)
Prior to the establishment of this experiment in 1999, the paddock had been a traditional, perennial pasture grazed by sheep. The plot area was 1.8 ha comprising nine 0.2-ha plots (20m width, 100m length). The three tillage treatments compared were raised beds (RB), conventional cultivation (CC), and deep cultivation (DC). Each treatment was replicated three times across the field in an east–west direction using a randomised block design. Each year except for 2001, the tillage plots were cropped with grains or oilseeds.
Surface runoff volume per unit area (mm) was measured from the RB, CC, and DC tillage plots. The tillage plots were hydrologically isolated using compacted earth mounds and surface drains along the perimeter of each plot. Flows were measured using modified Replogle-Bos-Clemmens type flumes with a throat width of 100mm and a hydrostatic water level sensor.
Crop measurements of grain yield and plant dry matter (t ha–1) were taken each year at harvest for each treatment. Regular visual assessments were made on the percentage groundcover and crop condition.
A natural logarithmic transformation, ln(runoff + 1), was used to stabilise the mean–variance relationship of the runoff data. The log-transformed data were modelled using a linear mixed model which included fixed effects for treatment, date, and the interaction of treatment and date. Random effects included replicate and plot effects.
Whightman et al (2004)
A field experiment was established in 1999 with a randomised block design of three cropped treatments (0.2 ha plots) replicated three times, plus one unreplicated pasture plot (1.5 ha). The treatments were:
1. Crops grown without raised beds (shallow cultivation to 0.08 m depth).
2. Crops grown without raised beds (deep cultivation to 0.15-0.20 m depth).
3. Crops grown on raised beds (deep cultivation to 0.15-0.20 m depth).
4. Pasture plot was on a similar soil type and gradient (1%) as the cropped plots.
In 2001, wheat (cv. Mitre) was sown on 3 August with 23 kg P/ha and 11 kg N/ha as mono-ammonium phosphate. The perennial ryegrass/subclover pasture plot was set stocked with merino wethers at 7 DSE/ha (district average) and topdressed with 9 kg P/ha as single superphosphate early in winter. Runoff volumes were determined using flow measuring flumes connected to a central datalogger. Automatic water samplers either collected water samples at 0.2 mm runoff intervals or following manual activation during flow events. Within 24 hours of collection, water samples were placed in -15oC storage, until they could be analysed for total nitrogen (TN) and total phosphorus (TP).
Project administration
Site identifier code: na
Principal investigator: JE Holland
Principal data manager: N/A
Principal organizations: University of Melbourne, Grains Research and Development Corporation
Data custodian: University of Melbourne
Key co-operators: N/A
Data access policy: Research has been published but base data is not archived
Planned pathway for data: completed study, no evidence of formal database records.
Data warehousing: for ongoing studies -na
Planned data upload frequency: for ongoing studies -na
Key references and sources of this data synthesis
These data summaries have been extracted from:
- Holland JE, White RE & Edis R. (2007). The relationship between soil structure and solute transport under raised bed cropping and conventional cultivation in south-western Victoria. Australian Journal of Soil Research 45: 577 – 585.
- Holland JE, White RE & Edis R. (2008). Improved drainage and greater air-filled porosity of raised beds in south-western Victoria. Australian Journal of Soil Research 46: 397 – 402.
- Holland JE, Johnston TH, White RE & Orchard BA. (2012). An investigation of runoff from raised beds and other tillage methods in the high rainfall zone of south-western Victoria, Australia. Australian Journal of Soil Research 50: 371 – 379.
- Wightman B, Peries R, Bluett C & Johnston T (2004). Permanent raised bed cropping in southern Australia: practical guidelines for implementation. 173-190.
Keywords:
South-western Victoria, texture-contrast, soil structure, convective lognormal transfer function, macropore, pore connectivity, high rainfall zone, waterlogging, soil physical properties, texture contrast soils, air-filled porosity, drainage, rainfall intensity, soil water balance, tillage treatments